Reactions of molybdenum(0) tricarbonyl complexes with 8-azidoquinoline. Crystal structure of the phosphinimine complex Mo(CO)4[N(PPh3)(C9H6N)] and evidence for a bent nitrene

Abstract

tron-transfer reactivity in these systems. Picosecond flash photolysis studies on M2(dba)3 (M = Pd, Pt) and Pd2(dba-Fc)3 are in progress.Acknowledgment. This research was supported by the NSERC and the FCAR. P.D.H. acknowledges Dr. D. James (Photon Technology Int.) for emission lifetime measurements and Mr. Yvon Couture (Université de Sherbrooke) for assistance in some of the electrochemical experiments.

Synthesis and Characterization of the First Mononuclear NiIIPhosphorane Imino Complex

“…The nitrogen atom is in an essentially trigonal-planar environment (Ni-N(1)-P(3) 123.9(4), Ni-N(1)-C(6) 113.8(5), and P(3)-N(1)-C(6) 121.2(5)°), and its hybridization does not affect the Ni-N distances which are 201.1(7) pm in 3 and 198.1(5) pm in [NiCl-(PMe 3 )(PNHMe)]PF 6 (PNHMe ) (o-diphenylphosphino)-N-methylaniline), 23 which contains an sp 3 -hybridized N-atom. The P-N bond distance of 158.9(7) pm in 3 is similar to the values observed in several closely related phosphorane imino complexes, and it is indicative of π interaction between P and N. 16,17…”

“…31 P{ 1 H} NMR (200 MHz, CDCl3): δ -15.6 (s, PNdP(CH3)3), 6.2 (s, PNdP(CH3)3). Although nitrene pathways have been postulated for the formation of phosphorane imines, [13][14][15][16][17][18][19][20] the nucleophilic amido pathway appears to be more plausible in the system we have investigated since (a) [HPMe 3 ] + is detected by 31 P NMR in the reaction mixture during the formation of 3 and (b) the concomitant addition of equimolar amounts of [HPMe 3 ] + 21 and 2,4-lutidine produces 3 in almost quantitative yield, upon starting from 1. Indeed, under these experimental conditions, the lutidine (pK a ) 6.99) is expected to selectively deprotonate the coordinated PNH 2 ligand to give 2*, while the trimethylphosphonium cation (pK a ) 8.65) provides the electrophilic fragment for the metal-assisted formation of the final phosphorane imine ligand (Scheme 1B).…”

Synthesis and Reactivity of [Tp‘(CO)(PhC⋮CMe)WNPh]+ (Tp‘ = Hydridotris(3,5-dimethylpyrazolyl)borate)

“…17 The putative electrophilic nitrene intermediate formed from the reaction of fac-Mo(PPh 3 )(CO) 3 (MeCN) 2 with 8-azidoquinoline reacts with triphenylphosphine. 18 Ambiphilic character has been observed for the nitrene in (CO) 5 W(dNPh), which forms the phosphinimine ylide [(CO) 5 W(N(PPh 3 )(Ph)] 19 upon reaction with triphenylphosphine and also reacts with a variety of aldehydes, ketones, and thioketones to form imines. 20 The role of electrophilic nitrenes as nitrene transfer reagents is an important aspect of their reactivity.…”

Palladium(II) Complexes of Monoaryliminophosphorane Derivatives of 1,2-Bis(Diphenylphosphino)methane. Crystal Structure of [Pd{κ2-C6H3(NN−C6H4Me-4‘)-2- (C6H4Me-4‘‘)-5-C,N‘}{κ2-PPh2CH2P(NC6H4Me-4)Ph2-P,N}]

“…The reported iminophosphorane complexes can be classified into two groups depending on the number of P atoms of the ligand. Those from monophosphines are known for Mo, W, , Os, Co, ,, Rh, − Ir, ,, Ni, Pd, , Pt, , Zn, Cd, Hg, and B . With only a few exceptions, − most complexes containing iminophosphorane ligands with two phosphorus atoms are bis(diphenylphosphino)methane (dppm) derivatives.…”